Effect of serial 5'-deletions of the rat HL promoter region on transcriptional activity in HepG2 cells. Experiments were performed as described in the legends to figure 4. Data were expressed as percentage of the ratio measured in the rHL-446 CAT – transfected cells, and are means ± SD from 3–5 independent experiments, each performed in triplicate. *: P < 0.05; n.s.: not significant.